Addon goes crazy on Paypal site. You cant even login.

This add-on would be useful for many people but on Firefox it just isn't usable. With Grammarly activated Firefox CPU usages goes through the roof on my Macbook. My Windows PC is bareable because it's a powerful machine, but on a slower work provided PC Grammarly is just too slow. I suspect Firefox's API just isn't providing the needed functions for Grammarly to work smoothly, but unfortunately this goes against the extension itself.

I don't need Grammarly because I have auto-correction

Grammarly sends up to 10k DNS requests to it's servers every day. That's 380 requests per hour! or 6.3 requests per minute! Queries servers are grammarly.io, grammarly.com, grammarlyaws.com.
Why would they do that?? Why would grammarly addon ask for IP of mothership server so often? Uninstalling this.